Papillary muscle rupture complicating acute myocardial infarction. Treatment with mitral valve replacement and coronary bypass surgery.

Six cases of complete or partial rupture of the papillary muscle after acute myocardial infarction are presented. All cases were treated by mitral valve replacement and concomitant coronary bypass surgery. An average delay of 3 days between rupture and operation occurred in the four patients with rupture of the main muscle trunk. The operative mortality rate was 50 percent. Such patients present with acute, florid left ventricular failure secondary to the severe mechanical burden imposed on the newly infarcted heart. The resulting valvular incompetence must be corrected by urgent mitral valve replacement if survival is to be lengthened. Patients with partial or apical head ruptures have a lesser degree of regurgitation and symptoms are largely dependent on intrinsic ventricular function. Both of our patients with partial muscle rupture presented with severe heart failure 2 to 4 months later, and both did well postoperatively. We believe that prompt operation without prolonged attempts at medical stabilization is the key to decreasing operative mortality, especially in instances of complete muscle rupture. Since ischemic heart disease remains the leading cause of death in such patients, coronary artery bypass surgery should be performed in conjunction with valve replacement.